EUVD-2026-41940Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from Vendor (GitHub_M) · only source for this CVE.
CVSS VectorVendor: GitHub_M
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
2DescriptionCVE.org
Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers before writing Traefik's own value, but do not account for underscore-variant header names, which many backends normalize identically to dashed forms. An attacker able to reach a protected route can inject an underscore-variant header that survives Traefik's stripping and reaches the backend alongside, or on the unauthenticated ForwardAuth authResponseHeaders path instead of, the value Traefik intended to set, spoofing identity or authorization context. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.
AnalysisAI
Identity/authorization header spoofing in Traefik reverse proxy (before v2.11.51, v3.6.22, and v3.7.6) lets an attacker reaching a protected route smuggle an underscore-variant HTTP header past the BasicAuth, DigestAuth, and ForwardAuth middlewares' sanitization. Traefik strips canonical dashed spoofed headers before setting its own trusted value but ignores underscore forms (e.g. …
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Traefik is an open source HTTP reverse proxy and load balancer. Rated high severity (CVSS 7.5), this vulnerability is re
types/types.go in Containous Traefik 1.7.x through 1.7.11, when the --api flag is used and the API is publicly reachable
Traefik is an open source HTTP reverse proxy and load balancer. Rated medium severity (CVSS 6.5), this vulnerability is
Traefik is an open source HTTP reverse proxy and load balancer. Rated medium severity (CVSS 6.5), this vulnerability is
Traefik (pronounced traffic) is an HTTP reverse proxy and load balancer. Rated high severity (CVSS 8.8), this vulnerabil
Traefik before 2.10.5 and 3.0.0-beta4 is affected by a denial-of-service vulnerability in HTTP/2 request handling inheri
In Traefik before versions 1.7.26, 2.2.8, and 2.3.0-rc3, there exists a potential open redirect vulnerability in Traefik
Traefik is an HTTP reverse proxy and load balancer. Rated high severity (CVSS 8.1), this vulnerability is remotely explo
Traefik reverse proxy and load balancer contains an mTLS authentication bypass vulnerability that allows attackers to ci
Traefik versions before 2.11.38 and 3.6.9 allow remote attackers to cause denial of service by sending incomplete TLS re
Denial of service in Traefik versions prior to 3.6.8 allows unauthenticated remote attackers to exhaust connection resou
Traefik versions 2.11.9-2.11.37 and 3.1.3-3.6.8 contain a case-sensitivity bypass in Connection header handling that all
Same weakness CWE-178 – Improper Handling of Case Sensitivity
View allSame technique Code Injection
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External POC / Exploit Code
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